The present invention relates to a connecting device for use with pneumatic or hydraulic multi-line hoses serving to connect pneumatic or hydraulic conduits to an appliance particularly, but not solely, for use in mineral mining.
It is well known to combine a group of conduits or the like within a flexible protective cover to form a multi-line hose and to terminate such a hose with a coupling employing plug-pins--see for example U.S. Pat. No. 4,247,135 and UK patent specification No. 1362807. Devices of this type are widely used in mine workings to supply pressure fluid to drive appliances or to control operations. In the known devices the individual lines or conduits are provided with the aforesaid plug-pins which are supported by a plate inside a cap or housing. Bores or slots in the plate locate the plug-pins on a common pitch circle. A complementary fitting, say on a valve block or unit, has sockets which receive the plug-pins and the cap around the plug-pins mates with a receptor on the fitting. It is also known to use an alignment element to ensure the mating components are correctly orientated with respect to one another. This centring or alignment element may take the form of one of the plug-pins which has a greater diameter than the remaining pins and engages in a corresponding larger socket. With the larger pin and socket correctly aligned the remaining plug-pins and sockets are correctly located. Normally devices and fittings of the type described are used in the cramped conditions which are encountered in underground mine workings. This aggravates the interconnection of the devices and fittings, despite the alignment elements, especially since the hoses are robust and not easily bent or twisted. Where a hose is to take an angular course it is necessary to have a comparatively large radius and this is not always feasible where space is cramped or where the valve block is located in an awkward position. In such circumstances the fastening or release of the coupling devices linking the hoses to the appliances can cause considerable problems. To overcome these difficulties an intermediate connector as described in German patent specification No. 3015809 can be used. Such a connector can be inserted between sections of multi-line hose or between such a hose and a valve block, for example. This connector comprises two tubes connected together in a flexible manner and carrying the appropriate parts to mate with the hose coupling devices and valve block fitting. This flexible connector enables relative movement between the parts to cope with the positional relationships prevailing.
The connector itself takes up considerable space, increases the overall cost and is not always reliable. Further examples of connectors or coupling devices are described in German patent specification No. 3003066 and in the aforementioned U.S. Pat. No. 4,247,135.
A general object of the present invention is to provide an improved form of connecting device.